Data processing materials



United States Patent @7 3,220,859 DATA PRCESSING MATERALS Elliot Berman, Braintree, and Charles H. C. Pian, Boston, Mass., assignors to Itek Corporation, Waltham, Mass., a corporation of Delaware Continuation of application Ser. No. 11,944, Feb. 15, 196i). This application Nov. 21, 1969, Ser.` No. 70,544

9 Claims. (Cl. 106-19) This application is a continuation of our co-pending application Serial No. 11,944 filed February 15, 1960, now abandoned.

The present inventions and discoveries in their broadest aspects relate to data processing and to improved media, including improved materials for rapid economical reception, reproduction, recording and storing data such ras coded and uncoded intelligence, documents, records, images and the like. More particularly, our invention and discoveries relate to novel materials for thermally responsive reception, recording land storage of such information to sensitize carrier materials adapted to be marked in accordance with the therrnographic techniques, and to combinations of such compositions and carriers as articles of manufacture.

Such carrier materials may be paper, cloth, cellulosic compositions for example, or other suitable web or sheetlike materials. The materials of the present invention are improvements over the iixable, thermal responsive materials disclosed in co-pending U.S. application Serial No. 860,008 of Leonard E. Ravich iiled December 16,

1959, now abandoned, and an application in continu-ationin-part thereof tiled on even date herewith. In particular, the present invention includes improvements in reducing thermal responsiveness of such materials after image formation by solvent rinsing or volatilization of the residual background compounds.

So far as known, prior thermographic papers and the like, except for those disclosed in said Ravich applications, have certain varying and differing disadvantages and undesirable limitations. A few of these disadvantages are that the image formed, when the sheet is exposed to heat, may be blurred, of poor or non-uniform color intensity and/or provide poor contrast with the copy sheet; moreover, exposure of the sheet may require heating for an undesirably long time period. Such sheets in some instances are sensitized by compounds in a wax layer which is relatively expensive to manufacture, and result in poor image resolution, which may be subsequently obscured by exposure of the sheet to further heat or radiation.

In said Ravich applications systems are disclosed and claimed in which permanent thermographic information markings are formed on sensitized carrier material and the latter is thereafter desensitized in the unreacted areas thus rendering the carrier incapable of further information obscuring color changes due to heat. The present invention also provides permanently iixable information carriers falling within the purview of the said Ravich disclosures with improvement of the quality of the sensitizing materials and images produced, obviates the abovementioned disadvantages of prior copy papers, and has the following general advantageous properties: inexpensive system; aqueous or common solvent solution for simplified manufacture; paper support or carrier not adversely affected; good stability under normal storage conditions; stable to ultraviolet radiation, eg., sunlight, for a prolonged duration; will not smudge; print is of archival quality; good sensitivity, i.e it does not require a high temperature (120 C.), or a relatively long time at a specific temperature, or heating over a Wide range of temperature to produce a visible change of sufficient in- 3,220,859 Patented Nov. 30, 1965 tensity; capable of producing information markings of good color intensity, sharp detail in the letter outlines, with no burn-out and spread of letter outlines; no etfect on the original so as to permit repeated use of the original; satisfactory copies are produced when subjected to relatively widely varied quantities of radiant energy; not over sensitive to impurities; and completely fixed, including rendering background no longer thermally sensitive, by water rinse, among others.

Reflex reproduction as herein referred to is effected by placing a radiation transmissive, thermally sensitive carrier material in surface contact with the image on the graphic original to be reproduced between said image and va radiation source which transmits radiation through the carrier to the iamge. The radiation passes through the sensitized material, is :absorbed by and increases the temperature of the marking areas of the original image sufficiently above the background or spacing area temperatures to reproduce the marking areas rapidly on the thermally sensitive carrier as a result of heat-conductive pressure contact, such for example as that disclosed in U.S. Patent No. 2,740,895 and 2,740,896 to Mi-ller; 2,891,165 to Kuhrmeyer; and 2,813,043 to Clark.

In direct reproduction as herein referred to the temperatures of the marking areas of the master are selectively raised above the spacing or background areas sufiiciently by irradiation or other suit-able means and immediately thereafter brought into contact with the copy carrier in a manner to reproduce a positive image by thermal foramtion of the marking areas.

The copy materials of the present invention may be utilized in either a direct, reiex, or any other thermally responsive marking processes. Use thereof in a reex process is limited however, to a radiation tnansmissive carrier material.

In fixing or fixation of a sensitized carrier in accordance with the present invention, the background areas are rendered incapable of forming an limage when exposed to certain conditions after the desired image has been formed by thermographic process.

Accordingly, it is a primary object of the present invention to provide improved and more stable thermally responsive graphic data materials.

Another object of the present invention is to provide sensitizing processing media compositions for thermally responsive graphic data processing media which provide permanent images and which may be iixed after image formation, i.e., the thermal responsiveness reduced by either a solvent rinse or volatilization.

Another object of the present invention is to provide solutions of sensitizing compositions that may be veasily and quickly applied to a carrier.

Still another object of the invention is to provide thermally sensitive carriers on which any one of a variety of differently colored images Imay be formed on a light background.

A further object of the invention is to provide a sensitized thermographic carrier inherently capable of reproducing a large amount of detail.

Still another object of the invention tis to provide thermally responsive gnaphic data processing media having the foregoing advantages and which may be produced at low cost.

Other objects and advantages of the present invention will become lapparent to those skilled in the art from the appended claims and following detailed description and accompanying drawing wherein:

FIGURE 1 is a table of examples of sensitizing compositions in accord with the present invention.

In accord with the present invention, colorless compositions are normally utilized consisting of a base ingredient such as an acid and a color forming additive, as alpha-sulfo-palmitic acid and pyrogallol, to make a carrier heat sensitive and useful for thermally responsive marking processes. (It is now noted that when the term carrier is used herein, it is assumed that web materials are to be included in the meaning of such term, unless specific intent to contrary is indicated.) Such a composition may be simply prepared by dissolving the chosen base ingredient and additive in a solvent, such as water, acetone, alcohol, etc., then impregnating or coating the carrier with the solution and drying the copy carrier at any convenient temperature below that at which the now thermally sensitive carrier will change color. In addition, one may add quantities of certain materials such as carboxylic acids, as shown in detail hereinafter, to enhance the stability of the composition.

Alternatively, the same procedure as just outlined may be followed except that, instead of a normally colorless organic acid and additive being used to sensitize the carrier, salts which, when heated, react to form a colored compound, may be used. For example, an acid salt of an amine and a fluoroborate salt may be used to sensitize a carrier which may be used in known thermographic copying machines. After a thermally sensitive carrier sensitized in either of the ways generally described above has been prepared, it is ready for use.

Having described the invention in general terms, specific examples of the invention and of the ways in which. the examples may be used will now be given. In connection with the preferred proportions given in each example, it will be noted that any desired amount of any of the examples may be easily obtained by scaling the quantities given either up or down as required.

The table of FIGURE 1 illustrates examples, read horizontally from a particular example number, of compositions formulated in accord with the present invention. The upper figure in each box of the table indicates the preferred relative amount of the particular ingredient in the example while the preferred range is indicated in the lower half of the box below the dotted line. gredients are broken up into general groupings classified as base ingredients, color forming additives, and solvents. In at least one example the base ingredient, boron triuoride-diphenol complex, also acts as a color forming agent.

The compositions having uoboric acid as a base ingredient are all desensitizable by volatilization which occurs after the image has been formed on the carrier by exposing the carrier to a temperature condition sufficient to permit volatilization of the composition of the carrier i but insuicient to cause a color change in the background areas thereof. In place of phloroglucinol as a color forming additive several other compounds give effective results such as, for example, sucrose, sorbitol, polyvinyl alcohol, A-naphthol, B-naphthol, 3-hydroxy-2-naphthoic acid, o-aminophenol, tartaric acid, pyrogallol and resorcinol.

In the rst group of examples the base ingredient is a sulfo-aliphatic acid, alpha-sulfo-palmitic acid and alphasulfo-stearic acid being given as illustrative examples of this class.

After making up the solution, a carrier may be impregnated therewith by any convenient method. Alternatively, the carrier may be coated with the solution by any known method. While a white carrier has been found to be particularly effective, carriers of other colors may be used. Even practically transparent papers, such as the glassine papers, make very satisfactory carriers which may, in turn, be used, e.g., as masters for copying systems such as the known diazo or photographic reproduction systems.

The impregnated, or coated, carrier is then dried, again by a convenient method. We have found, for example, that rapid and complete drying is easily accomplished at room temperature under a partial vacuum. However, the way in which drying is accomplished is not essential The into the invention, it being necessary only that the application of excessive heat be avoided to prevent discoloration of the now sensitized carrier. By taking this single precaution during drying, the sensitized carrier becomes ready for use. Since the alpha-sulfo-palmitie acid and the pyrogallol in or on the carrier are colorless, no visible change will have taken place.

When it is desired to use the prepared carrier in a reflex copy process for example, it is simply assembled with the master to be copied and the two put through conventional reproduction apparatus such as that designated by the trademarks Masterfax or Thermofax In such apparatus, when the master to be copied irradiated through the carrier by infrared radiations, a reflex copy is produced. It will be found that a colored copy of the image on the master is formed on the carrier. It will be imiediately apparent that the character of the original image will affect the copy, it being assumed that the original image is capable of thermographic reproduction. It is also apparent that the character of the carrier itself will affect the speed at which an image may be copied in that paper of different compositions and thickness transmit infrared radiations and conductive heat differently.

It has been found that a dark image on a light background is formed when the foregoing steps are followed. It will be noted that the molar ratio of pyrogallol to alphasulfo-palmitic acid in the solution given is l.5:1. A reduction in the relative amount of pyrogallol, say to the point where the molar ratio of the pyrogallol to the alphasulfo-palmitic acid is unit, will also produce satisfactory images.

It has also been determined by experiment that other color forming additives in place of pyrogallol are useful with alpha-sulfo-palmitic acid to sensitize carrier materials. For example, aromatic phenols such as phloroglucinol, beta-naphthol or `-hydroxy-Z-naphthoic acid may be used. The following table illustrates the effects of the use of a few color forming additives. Molar ratios used in Table 1 are the same as used in Example 1 set out below. The method of treating a carrier with the compositions of the present invention is substantially the same as that described above. The amount of solvent in the present compositions is not critical since it merely serves as a means of applying a dissolved composition to a copy carrier, and is thereafter removed as by drying. Among the organic acids with a color forming additive, the following example illustrated as Example l in FIGURE 1 of the drawing has been found satisfactory.

Example 1: Preferred Alpha-sulfo-palmitic acid g 1 Pyrogallol ..g 0.55 Acetone rnl-- 20 TABLE 1 [Base compound, alphasullopalmitic acid, 1 g.)

Color Forming Additive Image Color and Background Color Density Phloroglucinol, .55 g..- Brown Light tan. Phloroglucinol, .38 g Brown Almost colorless.

Beta-naphthol, .65 g- Medium brown Very light pink. 3-hydroxy-2-naphthoic ac Yellowish.

Almost colorless.

g. 8-hdroxy-2-naphthoic acid, Brown scribed in connection with Examplel l. It will be observed that a dark image on a light background will be formed. The composition is stable at ordinary room temperature for extended periods of time both before and after being used as a copy carrier.

Other carboxylic acids, such as citric acid, may also be substituted for the tartaric acid as stabilizers without any apparent difference in result.

Although discussion of specific examples of this invention has been restricted to compositions containing alpha-sulfo-palmitic acid, other sulfo-aliphatic acids also are operative to thermally sensitize carriers for graphic data indication production. For example, alpha-sulfostearic acid, in molar ratios of 1:1 through 5:1 with pyrogallol or phloroglucinol as the color forming additive and tartaric or citric acid as the stabilizer coated on or in a sheet from a suitable solvent, gives images with high contrast in a thermographic reflex process. The manner in which any of these compositions is prepared is the same as previously outlined in connection with alpha-sulfo-palmitic acid containing compositions.

There are also other acids, as sulfamic acid, which may be used according to the invention in a composition such as Example 8 set out in the drawing.

When this composition is made and used in the same manner as the composition of Example 1, it will be found that an image which approaches the color magenta or amethyst is formed on a colorless background.

All examples heretofore given have common advantages: the materials are soluble in many known solvents; the materials have a low order of toxicity; none of the systems are pressure sensitive; none leave any residues in the reproducing apparatus during the copying process; a rst surface image is formed when the carrier is impregnated with the materials; the carrier may be used as a master in other reproduction systems; and the materials may be easily and cheaply applied to the carrier by known coating or impregnating methods. Further, after the image has been formed the carrier may be xed, i.e., the sensitized background may be desensitized by application of a solvent rinse such as Water to the carrier. This may be done by contacting the carrier with a wet sponge or other porous material laden with solvent, or by immersion of the carrier in a solvent bath for a time suflicient to x the carrier by reducing its thermally responsive marking capability enough to provide permanent images, or by any other suitable application of the solvent. Other examples of this type involving a sulfonic acid are illustrated in Examples 13 and 14 wherein 4,4-diphenyl disulfonic acid and m-benzene-disulfonic acid are used with a color forming additive.

All the examples discussed thus far require that the thermally sensitive composition contain a sulfonic acid as a constituent part thereof before any image may be formed. Other compositions may be used with the carrier to form a desired image in apparatus such as the Thermofax machine. For example, many of the acid salts of amines will react with zinc fluoroborate at elevated temperatures to form an image. Example 9 is exemplary of such a composition. The components for this example may be prepared by making two solutions, as follows:

After the solutions are prepared, they are then mixed in equal parts by volume and used to impregnate a carrier in exactly the same manner as any of the examples 6 heretofore given. This composition provides a brown image.

It has been found that a single constituent may accomplish the same result as the compositions previously described. Thus, an image may also be generated in the carrier by the thermal decomposition of the boron trifluoride-diphenol complex. A satisfactory composition may be prepared simply by dissolving 10 parts by volume of the boron trifluoride-diphenol complex in 40 parts by volume of acetone or other suitable solvent. Example 12 is exemplary of such a composition. Since the boron triuoride-diphenol complex is a liquid at room temperature, it may be applied without a solvent. However, it is easier to impregnate the carrier with the aid of a solvent.

Other sensitizing compositions apart from the sulfonic acid and fluoboric acid types utilize a 40% zinc fluoroborate solution (60% water by Weight) with a solvent and color forming additive such as benzidine dihydrochloride or with a like amount of 2-amino-S-diethylaminotoluene monohydrochloride. Example 10 is illustrative of cornpositions of this type.

It is evident that numerous modifications of and departures from the specic examples described herein may be practiced by those skilled in the art without departing from the inventive concepts. For example, other aliphatic or aromatic acids, or even acids not in such classes as uoroboric acid may be used with color forming additives for specific purposes.

The invention may be embodied in other specic forms without ydeparting from the spirit or essential characterics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. A thermally sensitive composition for producing a sensitized carrier for use in thermally responsive marking processes, said composition forming color in response to heat and consisting essentially of a thermally responsive ingredient selected from the group consisting of (a) the boron triuoride-diphenol complex and (b) thermally responsive mixtures of a thermally sensitive acid reagent selected from the group consisting of a-sulfo palmitic acid, a-sulfo stearic acid, 4,4'diphenyl disulfonic acid, m-benzene disulfonic acid, fluoboric acid, and zinc uoborate in combination with effective amounts of a reagent forming color in the presence of said acid reagent under the influence of heat and selected from the group consisting of pyrogallol, phloroglucinol, resourcinol, a-naphthol, -naphthol, 3-hydroxy-2-naphthoic acid, N,Ndiethyl-p-phenylene diamine hydrochloride, benzidine dihydrochloride, 2-amino-5-diethylamino toluene hydrochloride, polyvinyl alcohol and o-amino phenol.

2. A composition as in claim 1 which additionally contains a solvent for said ingredients facilitating their application to a carrier.

3. A composition as in claim 1 which additionally contains a carboxylic acid stabilizer selected from the group consisting of tartaric and citric acids.

4. A composition as in claim 1 wherein said thermally responsive ingredients are an a-sulfo aliphatic carboxylic acid and a phenol.

5. A thermally sensitive color-forming composition for producing a sensitized carrier for use in thermally responsive marking processes, said composition comprising as its essential thermally responsive color-forming ingredients -sulfo-palmitic acid and 3hydroxy2naphthoic acid.

6. A thermally sensitive color-forming composition for producing a sensitized carrier for use in thermally responsive marking processes, said composition comprising as its essential thermally responsive color-forming ingredients m-sulfo-palmitic acid and pyrogallol.

7. A thermally sensitive color-forming composition for producing a sensitized carrier for use in thermally responsive marking processes, said composition comprising as its essential thermally responsive color-forming ingredients a-sulfo-stearic acid and phloroglucinol.

8. A thermally sensitive color-forming composition for producing a sensitized carrier for use in thermally' responsive marking processes, said composition comprising as its essential thermally responsive color-forming ingredients a-sulfo-palmitic acid and phloroglucinol, said composition additionally containing tartaric acid as a stabilizer, and a solvent for the ingredients facilitating their application to a carrier.

9. A thermally sensitive recording medium consisting essentially of a carrier and a thermally sensitive composition thereon, said composition forming color in response to heat and consisting essentially of a thermally responsive ingredient selected from the group consisting of (a) the boron trifluoride-diphenol complex and (b) thermally responsive mixtures of a thermally sensitive acid reagent selected from the group consisting of a-sulfo palmitic acid, -sulfo stearic acid, 4,4diphenyl disulfonic acid,

References Cited by the Examiner UNITED STATES PATENTS 2,748,024 5/1956 Klimkowski et al. 106-21 2,795,504 6/1957 Klimkowski et al. l06--l4.5 2,813,042 11/1957 Gordon et al. 25065.1 2,859,351 11/1958 Clark et al. Z50- 65.1 2,967,784 l/l96l Newman et al. Z50-65.1 2,980,551 4/1961 Thomsen Z50-65.1 3,102,812 9/1963 Welch 96-75 3,108,872 10/1963 McMahon 96-91 ALEXANDER H. BRODMERKEL, Primary Examiner.

JOHN R. SPECK, MORRIS LIEBMAN, Examiners. 

1. A THERMALLY SENSITIVE COMPOSITION FOR PRODUCING A SENSITIZED CARRIER FOR USE IN THERMALLY RESPONSIVE MARKING PROCESSES, SAID COMPOSITION FORMING COLOR IN RESPONSE TO HEAT AND CONSISTING ESSENTIALLY OF A THERMALLY RESPONSIVE INGREDIENT SELECTED FROM THE GROUP CONSISTING OF (A) THE BORON TIFLUORIDE-DIPHENOL COMPLEX AND (B) THERMALLY RESPONSIVE MIXTURES OF A THERMALLY SENSITIVE ACID REAGENT SELECTED FROM THE GROUP CONSISTING OF A-SULFO PALMITIC ACID, A-SULFO STEARIC ACID, 4,4''-DIPHENYL DISULFONIC ACID, M-BENZENE DISULFONIC ACID, FLUOBORIC ACID, AND ZINC FLUOBORATE IN COMBINATION WITH EFFECTIVE AMOUNTS OF A REAGENT FORMING COLOR IN THE PRESENCE OF SAID ACID REAGENT UNDER THE INFLUENCE OF HEAT AND SELECTED FROM THE GROUP CONSISTING OF PYROGALLOL, PHOLOROGLUCOINOL, RESOURCINOL, A-NAPHTHOL, B-NAPHTHOL, 3-HYDROXY-2-NAPHTHOIC ACID, N,N-DIETHYL-P-PHENYLENE DIAMINE HYDROCHLORIDE, BENZIDINE DIHYDROCHLORIDE; 2-AMINO-5-DIETHYLAMINO TOLUENE HYDROCHLORIDE, POLYVINYL ALCOHOL AND O-AMINO PHENOL. 